Motor vehicle heater



Jag. 27, 1942.

T. F. sPAcKMAN MOTOR VEHICLE HEATER Filed Sept. 22, 1938 lnder/ZET Patented jan. 27', 1942 MOTOR HEATER Thomas F. Spackman, Chicago, Ill., assignor to Stewart-Warner Corporation, Chicago, lll., a corporation of Virginia Appneetien september z2, 193s, serial Ne. 231,230

' ci sic-2) l Claim.

The invention relates generally to heating equipment for motor vehicles and the like, and more particularly to ways of supplying fresh air to` the riding compartment of a vehicle for use in conjunction with a heater to add to the comfort of the passengers.

e Heretofore wind seals-for the doors and windows of a motor vehicle have been suficiently imperfect to permit a substantial interchange of the air on the outside and the air on the inside of the riding compartment. This interchange in many ways was desirable under normal conditions because it provided means for replenishing the air in the riding compartment and removing therefrom the-vitiated air. However, the drafts present with this interchange vwere objectionable, and with improvements in seals designed -to eliminate s uch drafts, the air in the riding compartment soon became stuffy and close.

Furthermore, the moisture content of the air yin the compartment rises upon occupancy vand with stagnationof the air condensation uponthe windshield and windows takes place. Also, when the heater is turned down more thermal units are available in the radiator for the lesser amount of air circulated over the radiator and the airY supplied at lthe lesser rate is much warmer. A

Also of importance is-the fact thatv the improved seals for the automobile make the riding compartment a more or less sealed container in which pressure can be developed if air is injected into the compartment under pressure. This difficulty was exemplified in the past by the difficulty experienced for a while in closing the doors before suitable relief vents were provided. However, the vents which are provided for door closing purposes only operate when there -is appreciable pressure inside the riding compartment. Otherwise, if there is no pressure, the

vitiated air in the compartment remains there;

.to the discomfort of the passengers. Consequently, one of the objects of the invention is to moderate the heated air supplied to a sealed' riding compartment when the temperature of the air in the compartment approaches the comfort level.

Another object of the invention is to moderate the heated air supplied to the riding compartment by a heater when the -speed of air circulation induced by the heater is reduced.

Another object of the invention is to provid Aa means for boosting the speed of air circulation inside a riding compartment when the temperature of the air therein approaches' or exceeds the comfort level.

Another object of the invention is to provide.

an auxiliary air circulating device which assists the heater in a riding compartment to increase the speed of air circulation in the riding compartment when the temperature of the air in the compartment reaches a predetermined point which may be varied at will.

Another object of the present invention is to provide a heating system for sealed riding compartments wherein fresh air is forced under pres-l sure into a pressure vented riding compartment in a manner moderating the air supplied by the heater to replace the vitiated air in the compartment. i f

Another objectV of the invention is'to provide a heating system for sealed riding compartments wherein the heating and the circulation of air in the compartment iscarried on independently of air pressure differentials existing between the air inside and outside .of said compartment and fresh air is supplied under pressure to the compartment to condition the air supplied by the heater and to replace the vitiated air in the compartment.

Another object of the invention is to provide a device of the class described vwhich is simple in construction and operation, thoroughly effective in its use, and inexpensive to manufacture and operate.

Thesebeing among the objects of the inveni tion, other and further objects will become apparent fronithe drawing herein, the description relating thereto, and theappended claim.

Referring to the drawing:

Figure 1 is a side elevation of the engine compartment and the front part of the riding compartment of a motor vehicle showing apreferred installation of the invention; and

Figure 2 is an enlarged section of the thermostatic control and the electric circuit involved in the invention.

Referring to Figure l, a motor vehicle having a dash I0 separating the engine compartment l2 from the riding compartment uis shown with a heater I mounted upon the dash below the instrument panel I8.

- Reference may be had to the cao-pending apture supplied by the carburetor 241s drawn through the mixing chamber 22 into the combustion chamber 24 where the mixture is burned to form hot gases which, in turn, are drawn into the radiator 25 and discharged through a. tube 28 into the intake manifold 30 of the engine 32 under the force of the vacuum created in the manifold.

A motor 34 and a fan 38 driven thereby are located inside a shell 38 which houses the radiator 26 of the heater I6 and air drawn into the shell through the opening 40 is propelled over the radiator 26 in heat exchange relationship and returned to the' interior. of the passenger compartment I4l through the bell-like -deflector 42.

The heat capacity of the radiator is high and in this way air present inside the riding compartment I4 is rapidly heated for passenger comfort when the heater is started. Thereafter, the air is repeatedly heated and kept in constant circulation for the comfort of the passengers. However, it will be appreciated that not long after the heater has been functioning the tem- .perature of the air will rise above the'comfort point if the heater is permittedto continue at full operation. mounted on the instrument panel I8, or some other suitable piace, and the switch set to close a circuit which controls a blower 44 when the comfort level is reached. The blower 44 derives its vsupply of fresh air from in front of the engine cooling radiator 46 where the intake tube -48 ends )n a widened mouth 50. The mouth 5l faces into the air stream developed by the forward movement of the vehicle and with /the pressurebuilt up thereby at the mouth, freshl air is supplied in large quantities to the compaifhnent I4 when the blower 44 is-brought into operation to force air A thermostatic switch 43 is' fand the temperature thereof is low.

pressure tothe compartment. Not only this, but v the blower 44 develops a pressure which operatesA to replace progressively the vitiated air inside thev compartment by forcing the vitiated air out. of pressure vents provided for permitting easy closing of the doors.

Furthermore, th'e extra hot air developed by V the heater when the speed of circulation is turned A down is tempered in proportion to the increase of heat which it receives by the air supplied by the' blower. That is to Say, with the supply of fresh air from the blower 44,constant, more fresh air per volume will be added by the blowerv to the heater air wh'en the speed of circulation of the heater air is low and the temperature thereof is high than Will be supplied by the blower when the speed of circulation of the heater air is high Thus, whether the air supplied by th'e heater is comparatively hot or merelyv warm, the air supplied for passenger comfort by the heater and the blower combined is of a substantially uniform temperature throughout the operation of the system, regardless of changes in the temperature of the air supplied by the heater.

' Referring to the thermostatic switch 43 for certain details of its construction, a U-shaped housing 54 open at both sides for free circulation of air, is provided with a threaded aperture 56 upon one side thereof in which is threadediy received a -screw 58 manually.I driven by knurled head 60. An insulating block 62 is disposed between the open ends of the U-shaped housing where it is held in place by the nut and bolt as. sembly 64 and the insulating block in turn supports a spring 65 carrying a contact 56 which can be varied in position by turningthe screw 58.

Cooperatively mount with' th spring contact 66 is a bi-metal leaf i 5I carrying a contact 61 which, under the influence of temperaturev changes, is moved to and from the con-tact r66. Thus, the temperature at which the circuit controlling the blower is closed is varied at will by the knurled head 6l being tumed one way or the vother so that the effective temperature of th'e air supplied by the blower and heater together may through the' conduit 52 into the path of the heated air coming from the heater I 6. As a result, r

when the heater and blower are both in opera: tion, a turbulence is created by the conflicting paths of air movement developed by them respectively, whereby the hot, air 'supplied by the heater is moderated by the cold air supplied by n the blower, and the cold air in turn is tempered by the h'ot air so that neither source of air supply provides a dominating draft.

' In addition to this, the speed o f circulation of air inside the riding compartment I4 is increased when the blower 44 is brought into operation and .since the blowerV 44 isin-operation for all temperatures above and including the comfort' level, the increase of the speed of air preyents stagna- 'tion of warm air in the top of the; riding compartment, and thereby also prevents the condensation of moisture upon the win eid.

-Moreoven any back pressures that might be created inside of the riding compartment, by the injection of fresh air under blower pressure in no l be varied at will.

Consequently, although 'a single embodiment of A the invention has been shown and described herein, it will be apparent to those skilled in lthe art that various and further uses, modifications and changes may be made without departing from the spirit-and substance ofthe invention, the scope of which is commensurate with th'e appended'claim.

What is claimedis:

In-a heating system for the riding compartment of a motor vehicle or the like, the vcombination of 'a -heat exchange unit mounted in said,

compartment, means for circulating air inside of the compartment over said heat exchange unit and returning said circulated air along a predetermined path, an air injector for supplying air to said'compartment from outside the said compartment, means propelling all said outside air supplied to said compartment into the path .of air circulated by the circulating means immediately adjacent th'e outlet thereof, 'and temperature respo ve means proximate the intake of said air circ ating means for measuring the temperature of said compartment and controlling said supply of fresh to said compartment.

. THOMAS F. SPACDAN. 

